All righty, I got some readings.
I’m not able to say what was happening before, when I had things connected exactly the same for several trials, but it had to be a faulty connectors somewhere. I’ve done a bit more connector replacement and just general tinkering of the hoses.
They always were connected properly though, aside from the previous notes in diagram.
I’m glad I have the VCV and UFO replaced because I know they both work. And also because the previous VCV was completely unplugged and received soot internally for who knows how long.

When I have my gauge inserted at the top entry point, I get about 12 HG after a few moments of engine startup. Then when I drive around and press throttle, it bleeds off accordingly and goes down to around 1 or so. Not perfect but defiantly operable.
However my concern lies with the time it takes to “fill up” with vacuum after it’s been bled by throttle. If I bring it down to around 5 or 6 HG, it takes a good 20 seconds without pressing throttle for it to creep back up to 12 HG.
Is this by design? Or is it leaky connections..?
I could convince myself either way.
I have looked thoroughly through all of my resources for VCV adjustment, including a booklet I purchased, and I have found no mention how long it should take to fill back up to 12 HG. There is plenty of mentioning of how fast it should bleed, which is immediately. But not fill back up.
I started thinking that this may be by design so that the pressure hangs out around where it was in the event of irradic throttle use.

Any thoughts? My other thought is that if I had a small leak, it wouldn’t hold 12 at all. Correct? Or maybe that’s wrong and the leak is small enough that 12 can be held but it has an impact on re pressurizing.